Intraocular lenses (“IOL”) may comprise one or more fluids disposed therein. For example, some accommodating IDLs use fluid movement within the IOL, or a change in fluid pressure within the IOL, to effect optical power change in the IOL. Exemplary accommodating IDLs that include a fluid can be found in U.S. Pat. App. Pub. Nos. 2008/0306588, filed Jul. 22, 2008, and 2008/0306587, filed Jul. 22, 2008, the disclosures of which are incorporated herein by reference. Exemplary methods of accommodation in response to natural ciliary muscle movement are also described therein. For example, in the embodiment shown in FIGS. 3-5 in U.S. Pat. App. Pub. No. 2008/0306588, a fluid pressure increase in the optic portion causes the shape of the anterior surface of the optic portion to change, thereby changing the power of the lens. Silicone oil is an example of a fluid that can be used in an IOL. In the embodiment shown, the peripheral portion is in fluid communication with the optic portion, allowing, for example, silicone oil to flow between the optic portion and the peripheral portion. The bulk material of the lens includes anterior lens element 16, intermediate layer 18, and posterior element 22. The bulk material can also be considered to include the haptic bulk material in the peripheral portion of the IOL.
When fluids such as silicone oil are used in an accommodating intraocular lens, the fluid, over time, may tend to swell into the bulk material. This can reduce the amount of silicone oil available to drive the optical power change in the IOL. It is therefore desirable to minimize the amount of swelling into the bulk material. It may also be important to provide silicone oil that does not reduce the response time of the accommodating IOL.
Some IOLs rely on, or can benefit from, a substantially uniform refractive index throughout the IOL. It may therefore also be beneficial to provide silicone oil that has a refractive index that is as close to the refractive index of the bulk material as possible.
Improved fluids (e.g., silicone oils), their methods of manufacture, and their methods of use in accommodating intraocular lenses are therefore needed.